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Susceptibility for ventricular tachycardia and the correlation between
depolarization and orthogonal components of repolarization.
Alexandru Dan Corlan,
Milan Horacek,
Luigi De Ambroggi,
Anadolu Kardiyol Derg 7 Suppl 1:139-141, 2007
ABSTRACT
OBJECTIVE: There is a continuing need of methods to identify subgroups
of patients at high risk of ventricular arrhythmias in particular
after myocardial infarction (MI). METHODS: We performed a singular
value decomposition of repolarization potentials in individual recordings
in 134 healthy males in 203 males with old MI and without documented
sustained ventricular tachycardia (VT) and in 104 MI males with documented
VT. We considered the absolute correlation coefficient between the
first orthogonal component constructed by matrix multiplication
of the first left and right singular vectors and the QRS integral
(RT1) and a similar index for the second component (RT2). RESULTS:
Abnormally high (more than two standard deviations above the mean)
value of the RT1 had a 89% specificity for VT in MI patients. Abnormally
low RT2 had specificity of 87%. Both indices combined had a 97%
specificity. However sensitivity of the combined indices was only
13%. CONCLUSION: Abnormalities in the correlation of orthogonal
components of repolarization with depolarization are highly specific
for a small group of patients with old myocardial infarction at high
risk of ventricular tachycardia.
[Medline]